Tepidicaulis marinus gen. nov., sp. nov., a marine bacterium that reduces nitrate to nitrous oxide under strictly microaerobic conditions

Int J Syst Evol Microbiol. 2015 Jun;65(Pt 6):1749-1754. doi: 10.1099/ijs.0.000167. Epub 2015 Mar 4.

Abstract

A moderately thermophilic, aerobic, stalked bacterium (strain MA2T) was isolated from marine sediments in Kagoshima Bay, Japan. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain MA2T was most closely related to the genera Rhodobium,Parvibaculum, and Rhodoligotrophos (92-93 % similarity) within the class Alphaproteobacteria. Strain MA2T was a Gram-stain-negative and stalked dimorphic bacteria. The temperature range for growth was 16-48 °C (optimum growth at 42 °C). This strain required yeast extract and NaCl (>1 %, w/v) for growth, tolerated up to 11 % (w/v) NaCl, and was capable of utilizing various carbon sources. The major cellular fatty acid and major respiratory quinone were C18 : 1ω7c and ubiquinone-10, respectively. The DNA G+C content was 60.7 mol%. Strain MA2T performed denitrification and produced N2O from nitrate under strictly microaerobic conditions. Strain MA2T possessed periplasmic nitrate reductase (Nap) genes but not membrane-bound nitrate reductase (Nar) genes. On the basis of this morphological, physiological, biochemical and genetic information a novel genus and species, Tepidicaulis marinus gen. nov., sp. nov., are proposed, with MA2T ( = NBRC 109643T = DSM 27167T) as the type strain of the species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alphaproteobacteria / classification*
  • Alphaproteobacteria / genetics
  • Alphaproteobacteria / isolation & purification
  • Bacterial Typing Techniques
  • Base Composition
  • DNA, Bacterial / genetics
  • Denitrification
  • Fatty Acids / chemistry
  • Genes, Bacterial
  • Geologic Sediments / microbiology*
  • Japan
  • Molecular Sequence Data
  • Nitrates / metabolism
  • Nitrous Oxide / metabolism
  • Phylogeny*
  • RNA, Ribosomal, 16S / genetics
  • Seawater / microbiology*
  • Sequence Analysis, DNA
  • Ubiquinone / chemistry

Substances

  • DNA, Bacterial
  • Fatty Acids
  • Nitrates
  • RNA, Ribosomal, 16S
  • Ubiquinone
  • Ubiquinone Q2
  • Nitrous Oxide

Associated data

  • GENBANK/AB821371